ACROSSL down = 1973
A: a multiple of V across
H: a multiple of R across
I: third root of D down
J: a prime number
K: the digit sum of G down multiplied with a prime number
L: half the digit sum of L down
M: this multiple of T across is greater than C down
N: a multiple of T across
O: greater than the reverse of T down
P: a multiple of R across
Q: another multiple of R across
R: a divisor of P across
S: a multiple of J across
T: the digit sum of R across
U: a multiple of T across
V: K across multiplied by the prime number mentioned in the clue for K across

DOWNA: the reverse of N across
B: a multiple of P across
C: a palindrome
D: the third power of I across
E: Not a multiple of the digit sum of V across
F: a cubic number
G: the third power of K across
L: Rainer Typke's year of birth
N: the difference of the first two digits equals the difference of the last two digits.
O: a multiple of K across
P: not a multiple of T down
T: the reverse is less than O across